The invention relates to the field of pulleys and, more specifically, to pulleys that are intended to support a line such as a cable or cord. The grooved wheel of most such pulleys are housed in assemblies that require the line to be threaded onto the wheel in order for the line to be suspended by the assembly, wherein the assembly is in turn suspended by a hook to an anchored support member. The assemblies may be known as snatch blocks, tackle blocks or pulley blocks, for example, or when used in combination, they may be known as block and tackle assemblies.
The invention permits the line to be placed in the pulley without passing or threading it through the pulley and onto the wheel by a free end, an advantage that allows the line to remain secured at both of its ends while the line is fitted to the pulley. Others also have devised arrangements to fit a line to a pulley without the need for threading. They include the development disclosed by M. W. Schrader in U.S. Pat. No. 2,555,059, wherein a snatch block is shown and described as having a housing with a stationary side member that is attached to a snatch hook from which it can be suspended. The stationary side member supports one end of the journal pin on which the pulley's wheel is mounted. The other end of the journal pin is fitted to the opposite side member, which side member can rotate about the pin to open the pulley and allow a line to be placed on the pulley's wheel. Then, the moveable side member can be rotated into a closed position that prevents the line from being disloged from the wheel. A hook shaped extension near the top of the moveable side member fits into an arcuate groove in the stationary side member that has an undercut or modified dovetail bottom portion to which the tip of the hook conforms. A locking feature for when the snatch block is in its closed position, is formed by a spring loaded plunger in the stationary side member that snaps into a bore in the moveable side member. The pulley's wheel is somewhat larger in diameter than the diameter of the journal pin, and rides on a layer of lubricant that is introduced into the hub of the pin at a fitting of conventional design. The lubricant is communicated by passages which open into a brass bushing at the interface between the pin and the wheel of the pulley. The bushing is disposed on the pin and engages the bore of the pulley so that the pulley is journaled directly on the bushing for rotation between the stationary and moveable side members. A washer is slipped on the pin on each side of the wheel to separate the wheel from the stationary side member on one side and from the moveable side member on the other side. The front end of the journal pin has a head that extends forward beyond the moveable side member. The opposite end of the pin is threaded to receive a cap nut that extends rearward beyond the stationary side member.
Other pulley assemblies that have been designed to avoid threading the line through the pulley include the devices that are disclosed in a large group of patents that show swing away side members. The body of art is represented by U.S. Pat. No. 2,449,703 to C. B. Johnson, U.S. Pat. No. 2,633,329 to F. L. LeBus; U.S. Pat. No. 2,649,282 to J. E. Fate, Jr., and U.S. Pat. No. 2,754,084 to F. L. LeBus, Sr. Each shows a side member that is rotatable about the shaft of the pulley and engages with the pin that connects the hook of the snatch block to the pulley assembly. Other examples of the prior art are U.S. Pat. No. 2,762,607 to D. Anderson, and U.S. Pat. No. 4,056,257 to H. E. Kaiser, which disclose side members that each have a hook. The hooks are rotated apart about the shaft of the pulley to open the assembly and permit the introduction of the line, and are rotated back together to close the assembly and capture the line.